Thicker Than Water
by The Jabberer
Summary: Nanako didn't expect to get a little brother when she entered college.
1. Chapter 1

**TITLE: **Thicker Than Water  
**FANDOM:** Prince of Tennis  
**SUMMARY:** Nanako didn't expect to get a little brother when she entered college.  
**CHARACTERS: **Nanako, Ryoma, eventual light RyoSaku  
**DISCLAIMER: **I don't own Prince of Tennis  
**DEDICATED TO:** fyerigurl and doroniasobi. Happy belated and early birthday!  
**NOTE:** I know, Nanako gets out of her high school super early for the Japanese school year. Just go with it.  
**ANOTHER NOTE:** This didn't turn out as good as I wanted it to, but I'm just amazed I could write it all without alcohol.

.

When Nanako gets accepted into the prestigious Tokyo University, her parents can't be happier. But when they realize that she has to find an apartment in Tokyo, they begin to wonder if she'd like to go to the local college instead.

So when her uncle Nanjiroh asks her to take care of his property in Tokyo, she's thrilled. She gets live in a beautiful home, even if it _is_ close to a temple, for _free_. It's a fifteen-minute commute to her school, and in a safe area to boot.

When he tells her that he'll be moving in as well, she grins and tells him that she'll have the house in a livable condition when he arrives.

Echizen Nanjiroh, for all his antics (details of his brief but colorful life as a bachelor are well-known within the of-age members of the Echizen family), is her favorite uncle because, well, he's _interesting_. (Nanako loves her other uncles, but how many people can say that they're related to pro tennis players turned monks?) The fact that his wife, Rinko, is one of her life role models doesn't hurt, either.

Nanako also can't wait to finally get the chance to bond with her cousin Ryoma. He'd been quiet during his two visits to Japan, and the weekly phone calls that she has with him are rather curt, due to his slightly imperfect grasp on the language and his generally distant personality.

So when she finishes her senior year of high school, Nanako cheerfully buys some furniture for her new room on the Internet, packs her things, kisses her parents on the cheek, and moves to Tokyo within a week. She has the entire house clean and dust-free in three days. She acquaints herself with her new neighbors and the employees at the drug store, the convenience store, and the grocery store.

And then Nanako waits.

Little does she know, she's waiting for a brat.

.

The Echizens arrive a week after Nanako has settled in. It's early March, giving Ryoma plenty of time to become accustomed to speaking Japanese and, well, Japan before his school year starts in April.

When she hears the truck pull up to the house, Nanako beams, pulls on her flats, and runs outside to greet them.

"Welcome back!" she exclaims, bowing and running down the stone steps.

Her uncle grins easily. "Ah, Nanako-chan. You've grown up well. Gone and got yourself accepted into Tokyo U, I see."

"Congratulations," her aunt says, enveloping her in a hug. "We're very proud of you."

Nanako's smile grows wider. Rinko's embrace is as warm as she'd remembered. "It's good to see you, Oji-san, Oba-san."

When Rinko lets go, Nanako finally lets her eyes rest on her cousin. Ryoma is… surprisingly short, for all the tennis awards she's heard about. He's sporting a white Fifa hat and a tennis bag, and carrying an animal carrier.

"Hi, Nanako-nee-san," he drawls, giving her an obviously-rehearsed bow, "It's good to meet you. Please take care of me."

"It's good to finally meet you, too, Ryoma-san!"

Ryoma blinks. "Okay," is all he says before walking into the house.

Nanako stares.

Rinko sighs. "You'll have to excuse him. He's…"

"He's a brat," her uncle cuts in. "Don't mind him, Nanako-chan; he'll warm up to you soon enough."

Nanjiroh puts Nanako to work carrying some boxes into the house. He hands her one particularly carefully, giving her instructions to place it in a spare room and not to open it.

Naturally, she does.

"Oji-san!" she yells once he gets back inside, this time carrying a box full of clothes. "You told Kaa-san that you were done with those magazines!"

Nanjiroh rolls his eyes. "And the apples don't fall far from the trees, am I right, Ryoma?"

Ryoma snorts and tugs his cap down lower. "Mada mada dane, Oyaji."

.

That night, Rinko inspects the fridge that Nanako had stocked up earlier that week. "Well done," she says, obviously impressed. "I was expecting us to have to order in."

Nanako smiles. "Are you tired? Kaa-san taught me how to cook a little before I left."

"Shoo," Rinko laughs as she swats her out of the kitchen. "I got plenty of sleep on the plane. Just get Ryoma when I tell you to; tell him we're having Japanese, it's his favorite."

When Nanako goes to her cousin's room an hour later, she finds him playing with the strangest but cutest-looking animal she's ever seen.

"Is that a cat?"

Ryoma looks up, unamused. "His name is Karupin."

Nanako nods to herself, unable to tear her eyes away from the fluffy creature on her cousin's makeshift bed on the floor. "I'm sorry; he's very cute. We just don't have many cats like that in Japan."

Her cousin shrugs. "Mada mada dane."

Nanako pays him no mind as she sets herself onto the blankets, stretching a hand out gently.

"Hello, Karupin-san," she murmurs solemnly. "It's nice to meet you."

The cat, Karupin, sniffs her hand delicately and promptly begins to rub against it. Nanako giggles when the fur tickles her hand.

"Ah." Ryoma blinks, looking surprised and rather put-out. "He likes you."

"Good. I like him, too," she declares. "Karupin, do you want to join us for dinner? Oba-san grilled some fish you might like."

Karupin must understand her, because he meows and pads out the doorway. Nanako follows him out.

"Oba-san said you should come down now," she says before going through the doorway. "It's Japanese. Oba-san says it's your favorite."

"Yeah," he mutters sullenly, setting down the yellow cat toy and shuffling over. "I'm coming."

.

Dinner is fun, and Nanako finds herself a place in Nanjiroh and Rinko's stream of banter. But Ryoma, for the most part, is quiet, and all of his his occasional quips are directed to his parents.

When he heads back into his room, Nanjiroh sighs. "Don't mind him, Nanako-chan. He likes to be a brat when he first meets people."

Nanako just nods.

.

He's a brat for the next two days.

.

When Nanako heads down for breakfast at the end of the week, Ryoma isn't there. When she brings it up, her aunt and uncle laugh.

"He's not a morning person and he's finally adjusted to the time zone," Rinko says, good-naturedly rolling her eyes. "He'll probably wake up at one. I'll leave leftovers for him."

After breakfast, Nanako and Rinko fall into a routine of doing the dishes and badgering Nanjiroh into drying.

They sit in the living room for a bit, making a list of the furniture that Nanjiroh and Rinko need to buy for the day. When it hits ten o'clock, they leave for the furniture store. Nanako plays with Karupin for another thirty minutes before heading to a tea for the incoming chemistry majors at Tokyo U.

When Nanako gets back three hours later, her aunt and uncle have yet to arrive. She's about to set her purse down in her room when she realizes that Ryoma's bedroom is completely empty, save for a napping Karupin.

"Ryoma-san?" she calls, looking through the house.

He's nowhere to be found.

Nanako looks in the kitchen, and for some reason the discovery of untouched food makes her start to panic.

She checks the doorway, and notices a distinct lack of scuffed-up sneakers.

Nanako _knows_ that Ryoma isn't a five-year-old who's incapable of crossing the street by himself. But he'd lived in America for most of his life. His Japanese still has a slight accent, for Christ's sake. Her mother's crazy warnings about serial killers in the city come creeping back to her, and Nanako groans.

She reaches for her cell phone, only to remember that her relatives had yet to register their cell phones for Japan.

Nanako stands in the foyer, pursing her lips anxiously for all of ten seconds before she bolts out the door.

"_Ryoma-san!"_ she shouts once she's past the gates. When she hears no answer, Nanako blindly breaks out into a run, and her ears barely register the sound of her feet slapping the pavement. _"Ryoma-san!"_

She tries both the drug store and the convenience store, to no avail. The poor employees barely manage to decipher her hysterical descriptions of her cousin

Twenty minutes into her search, Nanako finds her cousin sitting on a bench at a nearby park, idly sipping a can of grape-flavored Ponta.

"Oh," Ryoma says when he registers to presence. "Nanako-nee-san."

Nanako is overcome with the urge to both slap him and hug him. She settles for staring at him in barely-contained hysterical relief for a good minute.

"Where," she exclaims, once she finally manages to breathe normally, "have you _been_?"

"A walk."

Nanako refrains from strangling him and places her hands on his shoulders to reassure herself that _yes, he really is here_.

"Ryoma-san," she says seriously, "I know that you're independent and perfectly capable of going on a walk by yourself. But next time, _please leave a note._"

"Sorry," Ryoma mumbles, looking at the ground. And then, alarmed, "Nanako-nee-san, your feet are bleeding."

"Oh." They look horrible, really, but to be quite honest, Nanako couldn't care less now that's found her cousin. "I forgot my shoes."

Ryoma suddenly looks much guiltier. "I saw a convenience store that way," he says, with much more authority than a twelve-year-old should have. "Wait here."

He returns five minutes later with a bag of rubbing alcohol, bandages, and a pair of flip-flops. "Here," he holds it out to her rather sheepishly.

As she busies herself with cleaning and bandaging her feet, Ryoma buys her a can of Ponta at the vending machine.

"It's grape," he mutters, opening it and placing it next to her spot on the bench.

Nanako smiles, despite the sting from the rubbing alcohol. "My favorite."

"Mine too."

Nanako finishes with the bandages, slips on her new flip-flops, and gets up to her feet, wincing. "Ready to go home?"

"Mada mada dane, Nee-san. You need to go to the hospital."

When she freezes, Ryoma rolls his eyes.

"Come on, Nee-san," he says, looping her arm around his shoulders and pulling her so that he's supporting some of her weight. "You have your wallet, right? Let's get a taxi."

.

The nurses and the doctor all tut over the state of Nanako's feet.

"What on earth made you forget your shoes?" they ask, shaking their heads.

Ryoma sits next to her, awkwardly holding her hand while the nurses pick out bits of gravel from her feet. If her grip on his hand tightens when they administer some shots or when the doctor gives her seven stitches, he doesn't mention it.

But as surprisingly patient as he is with Nanako, he's also surprisingly difficult with the hospital staff.

"Can she get a wheelchair?" he demands upon the doctor's instruction to avoid walking for the next few days to minimize swelling and bleeding.

The doctor smiles apologetically. "Now that we've properly cared for her feet, she should be fine for short bouts of standing and walking after a few minutes of elevation."

"Yadda," he says stubbornly. Nanako refrains from rolling her eyes, because a wheelchair _does_ sound nice.

The doctor stares at him, perplexed. "…What?"

"Yadda."

.

When they leave the hospital an hour later, Ryoma is smugly rolling Nanako out the doors and down the ramp.

Nanako is rolling her eyes, because Ryoma had taken a ten-minute detour to find the doctor and accidentally run over his toes.

.

Nanjiroh and Rinko are none too pleased when they learn the reason for Nanako's injured feet. Rinko promptly stocks the house with Nanako's favorite foods and orders Ryoma to take care of her every whim.

For his part, Ryoma does so uncomplainingly.

They develop a routine. For the next two days, Ryoma manages to wake up at a decent hour to roll Nanako into the dining room for breakfast. He plays a tennis match with his father while she chats with Rinko in the living room. Ryoma returns when his mother leaves for work, and they spend the rest of the day lounging on the couch, eyes glued to the screen.

Nanako takes the time to introduce him to some dramas. Much to her exasperation, he sleeps through most of them but somehow manages to wake up for every fight scene.

("Really?" she asks, poking him awake. "Ryoma-san, you're missing all of the plot."

He shrugs and yawns. "I could probably guess the plot if I wanted to."

She doesn't have a reply for that one.)

Once the swelling in her feet start to go down, Ryoma keeps her company during her short walks around the block. He smirks when she takes her first few clumsy steps, leg strength somewhat diminished after a few days of inactivity.

"Mada mada dane, Nee-san."

.

Almost a week after The Incident, Nanako (reluctantly) tells Ryoma that he can stop catering to her every whim. He shrugs, looking as apathetic as ever, but continues to join her during her drama marathons.

One particular day, Nanako and Ryoma find themselves sprawled under the new _kotatsu_ that Rinko had insisted on proudly displaying.

("Sixty percent off!" she always preens.)

They are watching an episode of one of Nanako's favorite older dramas, _Dr. Jin_, and eating her favorite milk-flavored ice cream bars, when Ryoma suddenly says, "I had a brother, once. He left and never came back."

His voice sounds as aloof as ever, but Nanako isn't fooled. She's starting to know her cousin well–she can read the sudden inward curl of his shoulders, the clench of the hand supporting his cheek, and his pointed determination to look at Karupin's tail.

Nanako's face softens, because she remembers the story behind Echizen Ryoga very well.

When Nanako was little, her mother had nagged at her uncle during one of their weekly phone calls about forgetting the importance of _safety_ during his days as an idle bachelor and reminding him of Rinko's sainthood for not even batting an eyelash.

_("But then again,"_ she'd said, _"she'd told me once that she couldn't believe you hadn't gotten anyone pregnant before you met her. I guess she was right."_

"_Stop nagging at me, sis. You're lucky you have me on speakerphone with Nanako-chan there, or else I'd be saying something very different right now,"_ had been her uncle's exasperated reply. _"Do you want to talk to Ryoga or not?")_

The weekly conversations after that had been full of stories of a little Ryoma stubbornly trailing after Ryoga. Family pictures had started featuring two cousins instead of one–they'd even worn matching sweaters on a Christmas card. But when the Echizens finally visited Japan, Ryoga had not accompanied them. Nanako's mother had made her eat all the oranges in the house during the week before their arrival.

"_Your uncle lost custody,"_ her mother had told her on the car ride to the airport. _"Remember not to mention him. They're very sad about it."_

Nanako can't help what she does next. She'd like to say that she hugs him, but that would really be putting it too gently. What she _really_ does is flop over on top of her cousin's back, wrap her arms around his tiny shoulders, and squish him as hard as she can.

"Nee-san," Ryoma grumps. "Get off."

Karupin blinks up at them before sprawling onto the ground with a quiet _thump_, tail swishing idly.

Nanako laughs. "No," she says, hugging him tighter. "I'm never ever _ever_ getting off."

He snorts, but Nanako _definitely_ notices the way he relaxes. "Do what you want."

.

When her feet completely heal, they're littered with discolored scars.

Nanako wears them proudly.

.


	2. Chapter 2

**TITLE: **Thicker Than Water  
**SUMMARY:** Nanako didn't expect to get a little brother when she entered college.  
**CHARACTERS: **Nanako, Ryoma, eventual light RyoSaku  
**DISCLAIMER: **I don't own Prince of Tennis  
**NOTES:** So sorry for the brevity.

.

Nanako and Rinko are pleased with the progress of Ryoma's affiliation when they realize that there are only two weeks left before Seigaku starts its first term. His American accent is now barely noticeable, and he's starting to remember to mind some basic manners.

Their delight is abruptly cut short when Ryoma asks if Sanada Yukimura was a real samurai.

Nanako attempts to get him caught up on Japanese history by dragging him through all the exhibits at various museums and marathoning all of the accurate historical dramas she remembers. Ryoma tolerates this as well as a twelve year old possibly could for three days. (This means that for three days, he grumbles under his breath and scowls, but otherwise goes along with it.) It's only when Nanako realizes that his reading skills are subpar at best and starts quizzing him on various kanji characters that he snaps.

"Yadda," he declares the fourth morning, plopping down onto the steps of the Edo-Tokyo Museum.

Nanako opens her mouth and then closes it again. "Ryoma-san, I didn't even _say_ anything."

"Yadda." Ryoma eyes the brochures in Nanako's hand in distaste and tugs on his hat. "Nee-san, you haven't even been to Harajuku yet, have you?"

She flushes. "I… Ryoma-san's education is much more important!"

Ryoma rolls his eyes–a habit that Nanako suspects he's picked up from her. "Yadda," he says again. "We're going to Harajuku today. And a cat café."

It takes the better part of the hour for her to finally acquiesce, but damn if Nanako isn't going down without a fight. She turns the train rides into opportunities to educate her cousin about J-pop.

"Heh," he says, when Utada Hikaru comes on. "It's good."

Nanako beams. "She's my favorite artist! Ryoma-san, let's go to a concert sometime."

He shrugs, but she doesn't miss the way he looks carefully at the names of the songs for later reference.

Ryoma, in turn, shows her Top 40 American music.

"Who is this?" Nanako asks eagerly when a particular song starts.

"Taylor Swift." And then, "Heh, you _would_ like her, Nee-san."

.

Harajuku is probably the most fun that either Ryoma and Nanako have had in a while.

Ryoma, it seems, has the uncanny ability to find cat cafés because they end up visiting a grand total of three. Nanako's favorite is a relatively unknown one with five cats, who like rubbing their faces against them once they register Karupin's scent. But she is disappointed that none of them have a cat as fluffy as Karupin.

"Duh," Ryoma scoffs. "Karupin's Karupin."

Then he flashes the bobtail in his lap a smirk. "Mada mada dane."

.

In-between the cat cafés, they take the time to see some tourist attractions, like Yoyogi Park, where they watch street dancers.

"Does Ryoma-san dance?" Nanako asks, playfully.

Ryoma snorts dismissively in an all-too-obvious attempt to avoid the question. "Do you?"

There must be something about Harajuku that makes people act uncharacteristically, because she promptly does a stiff wave with her arms, triggering an appreciative look from a nearby street dancer.

Ryoma smirks. "Your first fan."

"At least I have one," Nanako says, shoving him gently. "I think I want to go somewhere peaceful now, Ryoma-san. We can always go to the Meiji Shrine; it's where–"

"Yadda." Ryoma grabs her arm and drags her off in a random direction. "I see another cat café."

.

Ryoma ends up falling asleep on the train ride home, sprawled out shamelessly over half a row of seats. Nanako has to wake him up and lead him out of the train when they reach their stop


End file.
